Display cases

I have been all over the Internet looking, and I can't find this; what I am after is a clear display box... I want to have it 4x4x6 inside, so I can mount a photo to the back, and display something in the middle. I am probably going to make my own wood base, but I can't find the box for cheap (under $20)
It doesn't really have to even have a bottom in it, just something to put over the top to keep the object from being broken. (it is a hatched eggshell that is very special to me, as 99% of people have never seen this kind of egg)

Any help would be much appreciated... I thought maybe someone here would know where to find something like this.

Try a local glass shop they should be able to craft your box of glass or acrylic for a fair price.

What type of egg is it?

It is an Eastern Whip-Poor-Will. While it is illegal to take wild bird eggs, this one was hatched, and I have pics to prove it. It is just a small piece of shell, and since the baby bird was finished with it, I think it is legal to keep.

Thanks for the advice!